This invention relates to a switch device for an appliance for personal use, comprising an appliance switch actuator for activating and deactivating a driving member capable of being electrically operated in a housing of the appliance, as well as a locking device movable into the actuation path of the appliance switch actuator.
An automatic safety device guarding against accidental operation of rechargeable electric shavers and toothbrushes is already known, comprising a tappet which is carried in the housing and movable against the action of a spring and whose inner end is displaceable into the actuation path of an on-off switching member which is in the off position. In this arrangement, the direction of displacement of the tappet is transverse to the direction of displacement of the on-off switch so that a relatively large amount of space is required for the safety device (DE-PS No. 33 15 643).
By contrast, it is an object of the present invention to provide a switch device of the type initially referred to in which an appliance switch, when in the off position, is reliably guarded against being brought into an on position. It is a further object herein to provide a switch device which is easy to manipulate, can be accommodated in a minimum amount of space and requires a minimum number of components.
These requirements are satisfied in a switch device of the type initially referred to in that the appliance switch actuator and/or the locking device include engagement means which are displaceable into one another or interengageable for securing the appliance switch actuator relative to the locking device in the off position. The use of interengageable positive and frictional engagement means provided on the appliance switch actuator and on the locking device affords a simple method of wedging the application switch actuator relative to the locking device in the off position of the appliance switch actuator, thereby safely locking an appliance switch in the off position so it cannot be actuated in any way, in particular not by accident.
The present invention admits of a variety of embodiments which afford the common advantage that engagement means, in being suitably matched relative to one another, are formed on or molded into three structural elements of the appliance which are operatively associated with one another and include the stationary partition wall of the housing or housing wall, the appliance switch actuator and the locking device.
In an embodiment of the switch device permitting considerable space savings to be realized, the appliance switch actuator and the locking device are mounted on a backing member of the appliance housing in a manner enabling them to be displaced in the same plane of motion. This permits the switch device to be built to a minimum height.
Preferably, the appliance switch actuator includes at least one positive engagement means which is maintained in predetermined switch positions by means of at least one locking member provided on the backing member. For locking purposes, the locking device includes latch members displaceable into notches provided on the backing member. In an embodiment of the invention, the positive engagement means of the appliance switch actuator is an L-shaped resilient latch member having a knob formed on its leg. In a further embodiment of the invention, the positive engagement means of the appliance switch actuator is a U-shaped latch member having a knob formed on each of its elastic legs. In an embodiment of the invention, the positive engagement means of the appliance switch actuator is a bolt formed on the appliance switch actuator. In an embodiment of the invention, the locking member is formed of a web member situated between two oblong openings provided in the backing member. In an embodiment of the invention, the locking member is a bolt formed on the backing member. In an embodiment of the invention, the locking member is a U-shaped latch member formed on the partition wall with a knob on each of its resilient legs. To prevent the positive engagement means of the appliance switch actuator from sliding out of predetermined notches, the locking device includes at least one frictional engagement means which is displaceable into the displacement path of the resilient positive engagement means of the appliance switch actuator.
In another embodiment, the effect identified in the foregoing is accomplished in that the locking device includes at least one frictional engagement means displaceable into the displacement path of the resilient legs of the locking member of the partition wall. The frictional engagement means is preferably an L-shaped latch member which, in the off position of the appliance switch actuator, is adapted to be slipped onto its positive engagement means. In a further embodiment, the frictional engagement means is a U-shaped latch member the legs of which are adapted to be slipped onto the legs of the positive engagement means of the appliance switch actuator in the off position of the appliance switch actuator. In a still further embodiment, the frictional engagement means is a U-shaped latch member whose bar connecting the legs is slidable between the legs of the positive engagement means. The knobs provided on the latch members of the appliance switch actuator and of the locking device provide simple constructional means for accomplishing an operating sequence of both, including a latching function, in that for the knobs of both the notches are formed in at least one of the longitudinal sides of the partition wall by means of projections formed thereon.